When you say the 'usual' function keys... do you really mean some other system's function keys? Why would you expect macOS to use the same function keys as a different system? There's no standards body for these things.
Yes there is -- it's called CUA (Common User Access)
"The subset of CUA implemented in Microsoft Windows or OSF/Motif is generally considered a de facto standard to be followed by any new Unix GUI environment."
Apparently[1] the original intent was to allow the user to just type and rename the file, but the enter key was quickly added after they noticed that the display models all had garbage filenames. It was an early tweak that stuck (much to the chagrin of those of us who also use other systems). Why they never added it to the context menu is beyond me.
[1] https://www.folklore.org/StoryView.py?project=Macintosh&stor...
But I would argue F2 is less obvious. It's only obvious if you learned it at some point or if you were there when F2 was chosen. Enter is at least a normal text editing key for day to day typing, and it's already the bookend key to finish typing a new name.
My head-cannon about this is that for consistency within macos, all actions must be cmd+something, so is cmd+O for opening a file. In the terminal you can also use the "open" command which opens the file or the directory (I use "open ." a lot, I find faster navigating in the shell that in the finder).
Which is why I always try Cmd+R for renaming a file and then nothing happens.
Now I've used windows for a decade, and I still overall dislike it. But that doesn't mean these things are done "wrong" they are just done differently and not how I'd expect.
Windows doesn't place the light switches where I'm accustomed to. For example hy are there so many menus bars on each window. It's simpler to always know where the menu is at the top and it creates less screen clutter. Why does windows quit a program when close the document. If I wanted to quit it, I would have quit it. I just wanted a new document. These are just a few of the things that aren't bad but just aren't the philosophy I'd come to expect. Control-alt-delete to log in? Why?! I can't hit that one handed easily! Good thing I have two hands. And yeah bash or shell is kinda mess, but powershell is a verbose and has bureaucratic feel. It's just not my cup of tea but that doesn't mean it's wrong.
One of my favorites just happened yesterday with finder - I was trying to figure out how to rename a file, well the usual fx keys aren't doing it so the common process was to go to the toolbar context menu where hotkey is indicated next to the action's text. Rename for some reason had no hotkey indication! [1] so naturally I'm thinking it's somehow not bounded, google around for hotkey editing etc just to findout it's the least obvious key: return.
1 - https://i.imgur.com/LtcrBPU.png